var pdfWin = null;

function popPDF(url) {
	if (pdfWin && !pdfWin.closed) {
		pdfWin.location.href = url;
	} else {
		pdfWin = window.open(url,'pdfWin','height=450,width=680,scrollbars=yes,resizable=yes');
	}
	pdfWin.focus();
	return false;
}